How is the j1939 resistor enabled
thanks
How to enable the 1939 resistor
- marcio
- Posts: 4
- Joined: Mon Jan 17, 2011 1:53 pm
- jpurdum
- Enovation Controls Development
- Posts: 153
- Joined: Mon Jun 21, 2010 11:19 am
Re: How to enable the 1939 resistor
I've attached an example config that allows you to enable / disable the Plug A resistor from the screen. There are a couple of things to know about setting and clearing the resistor on the PV750:
- the resistor value is read at startup, so you must reboot the display for it to take effect. The assumption was that we didn't need to make this dynamic since it's really a cabling issue.
- the resistor variables need to be made non-volatile. The two resistor variables are
UserDefinedVariable.PlugA.Resistor
UserDefinedVariable.PlugB.Resistor
(the NMEA port on Plug D does not have a resistor available)
You can make sure it's non-volatile by making sure the Save Values: is checked when you select this variable on the Database tab. I noticed since I used the Blank Config that the variable is not set to non-voltile in that base config, so I had to change it in this one.
Understanding these two points should make it easier to understand this config and why it's set up the way it is. It was easy to test, when the resistor is set and I reboot, I did not get any CAN errors. When it is cleared and I reboot, I get nothing but CAN errors.
john p.
- the resistor value is read at startup, so you must reboot the display for it to take effect. The assumption was that we didn't need to make this dynamic since it's really a cabling issue.
- the resistor variables need to be made non-volatile. The two resistor variables are
UserDefinedVariable.PlugA.Resistor
UserDefinedVariable.PlugB.Resistor
(the NMEA port on Plug D does not have a resistor available)
You can make sure it's non-volatile by making sure the Save Values: is checked when you select this variable on the Database tab. I noticed since I used the Blank Config that the variable is not set to non-voltile in that base config, so I had to change it in this one.
Understanding these two points should make it easier to understand this config and why it's set up the way it is. It was easy to test, when the resistor is set and I reboot, I did not get any CAN errors. When it is cleared and I reboot, I get nothing but CAN errors.
john p.